Your pool water is constantly being invaded by phosphates.What are phosphates?Phosphates are a primary nutrient or food source for algae*.If you starve algae of this important food source, it cannot grow.Phosphates enter your pool from a variety of sources, including:

lawn & garden fertilizers

chemicals & cleaners

rainwater & fill water

body fluids & waste

decaying vegetation

and the list goes on...

These phosphates build-up in your pool water, providing a necessary food source and bloom environment for algae. Typically, algae is treated with harsh chemicals like algaecides or other sanitizing products. This is where PHOSfree shines.